LaserSoft Imaging

I was very excited to hear that the latest version of Silverfast supports HDRi and iSRD on certain Epson scanners (including mine).

I then spent a fair bit of time trying to figure out why "64-bit HDRi" was not showing up as an option. On a lark, I decided to switch from reflect to transparent, then voila, 64-bit HDRi was available. I switched back to reflective, and it was gone again.

Nowhere in any of the press or documentation had I seen this limitation. Is it a known limitation? Is it a permanent one?

I know the Perfection 4870 supports ICE for reflective sources, so I was under the impression that it had an infrared lamp under the bed as well as in the lid (TPU). Is that incorrect, or is it just that Silverfast hasn't added support for that lamp yet?

Dear pjc

As far as I know, ICE and the infrared technologies where made to work only with transparencies not with reflective material.

Cheers

I did a little more digging, and found some further detail in the Epson Perfection 4990 sales guide.

What is DIGITAL ICE technology?
DIGITAL ICE is a hardware/software technology that automatically removes dust and scratches from film, and corrects the marks left from tears, folds and creases in photos.

This indicates that, as I had thought, ICE does support reflective materials in addition to transparencies.

However:

How does DIGITAL ICE technology work?
For film scans
Four channels are used (Red, Green, Blue, and Infrared) to acquire an image. The IR channel detects 3 dimensional surface defects found on the original image.

The image is scanned twice, using a different angle of light each time. Each scan captures the original image, as well as its surface defects. Due to the two angles of light, surface defects reflect different highlights and shadows on each of the two scanned images. These differences are used to create the defect channel, which identifies and maps the location of surface defects.

I think it's clear from the first paragraph that, as you suspected, IR is used only for transparencies.

However, the second paragraph seems to apply to reflective materials, which raises the question: could Silverfast create the equivalent of an IR channel from this computed defect channel? If so, that would be an awesome improvement to HDRi and iSRD!

Dear PJC,

Thanks for posting that information.

Again ICE is a technology that only works with transparent materials (and not even all kinds of them, e.g. it has problems with B & W and some Kodachrome emulsions).

I do not see anywhere that Epson or Kodak (which created and patented ICE) state anywhere the use of ICE with reflective material.

pjc wrote:This indicates that, as I had thought, ICE does support reflective materials in addition to transparencies.

Again, I do not see it anywhere explicitly indicated. I think that might be your interpretation of the information you have quoted.

pjc wrote:However, the second paragraph seems to apply to reflective materials

Might seem so. But it does not

I am sorry, it is phyisically not possible

The scanner has a special infrared lamp which only works with the transparency unit.

However I must acknowledge it is a fantastic idea,it would make a great invention!

Cheers

LSI_Morales wrote:I do not see anywhere that Epson or Kodak (which created and patented ICE) state anywhere the use of ICE with reflective material.

From Epson's web site:

Digital ICE for Prints uses two lamps at different angles to map defects using differences in shadows to detect tears, folds and creases on prints and correct the scanned image accordingly.

As you observe, the infrared lamp is only used for transparencies, but Epson scanners that support "Digital ICE for Prints" have multiple lamps to detect surface defects. Again, it would be fantastic if Silverfast could convert this surface defect information into a calculated "i" channel for HDRi that can be subsequently used with iSRD.

Epson does now offer Digital ICE for prints as well as film. It is included with the v700, v750, and now the v600 scanners. Description is - "Powerful Image Restoration
DIGITAL ICE for Prints removes the appearance of tears and creases from damaged photos; DIGITAL ICE for Film removes the appearance of dust and scratches from film"
You can find this on the Epson website and on amazon.com you can see examples of it's use on prints under each of the scanners descriptions. This print technology is one reason for my purchase of the v600 scanner.

Dear Fellas,

First of all thanks for sending the links to the product sites of Epson (and Amazon). Effectively they market digital ICE for prints.

To clarify this misunderstanding I will go over a few concepts that will allow us to correctly understand this topic.

What is HDRi and how does it work?

HDRi is a file format that allows the creation of raw files in 64 bit color or 32 bits greyscale saved as TIFF, using transparent material.
In the case of 64 bits color it uses 16 bits of information per channel (r,g,b) and additional 16 bits for the infrared channel. With the 32 bit greyscale raw format, 16 bits will be used to write luminance values and another 16 bits for the infrared channel.

Basically to be able to have an HDRi file you need an infrared channel.

What is digital ICE?

It is a technology based on the use of infrared lamp for correction of scratch and dust on film. It was invented and patented by Kodak and is briefly described here: http://motion.kodak.com/US/en/motion/Products/Lab_And_Post_Production/dice.htm

It was developed in the Kodak Austin Development Center and a more detailed description of how it works can be found here: http://asf.com/products/ice/FilmICESpecs/

As you can clearly see, this technology and the use of the infrared lamp can only be used on film (and if you carefully take a look at other sites and warnings described there you will see that it does not even work with all kinds of transparencies).
Reflective material (as the word indicates), reflects light, it would also reflect the infrared channel.

So, by now you might be wondering: How come they publish this when the use of infrared lamp is not possible with reflective material?

Actually they are not completely lying, Kodak developed a software solution based on the information contained in the red, green and blue channels of the reflective material and they called it "Digital ICE photo print technology".

They do not explain in detail how it works, they say it is basically done in three steps:

1. Corrections for scanner system variables
2. Generation of an accurate defect map
3. Defective pixel correction algorithms

Where they claim to use proprietary algorithms (no further information)

A description here: http://asf.com/products/ice/FlatICESpecs/

As you can clearly see, the "Digital ICE photo print technology" does not make any use of the infrared channel of the scanner (it is just not possible).

In conclusion, if there is no infrared channel, there can not be any HDRi raw file.

I hope this helped clarify the reasons why it is not possible to create 64 nor 32 bit HDRi raw files with reflective material.

Thanks for your contribution and understanding

Greetings

Thanks for your reply and explanation.

I understand that Digital ICE for prints is different for film and prints and that film support is based on the infrared and differences in transmission to create an editing mask. However I think the bottom line for me on this particular subject is "Will Silverfast support this ICE for prints option when doing the scans with scanners which have it?"

I haven't received my v600 yet and so haven't had an opportunity to see it in action or to observe where this additional ICE capability is implemented, i.e. is it built into the scanner or is it just incorporated as a function within the Epson scanning software? If it is is built into the scanner, then I would hope Silverfast could invoke in the same way that it can turn on the infrared channel for a scan.

I realize the v600 is a new scanner and isn't supported yet, but the v700 & v750 scanners also tout this ability. Is it supportable or invokable in Silverfast when scanning prints with these devices?

Thanks.

Dear highyoyo,

highyoyo wrote:I haven't received my v600 yet and so haven't had an opportunity to see it in action or to observe where this additional ICE capability is implemented, i.e. is it built into the scanner or is it just incorporated as a function within the Epson scanning software? If it is is built into the scanner, then I would hope Silverfast could invoke in the same way that it can turn on the infrared channel for a scan.

It is hard to say, although we work in close cooperation with Epson, we do not work in any way with their own software, we only use their driver to communicate the scanner, the computer and SilverFast.

Usually, ICE is licensed by Kodak to another manufacturers under different types of concessions, sometimes those manufacturers are allowed only to use their technology in their devices but they do not have any control over ICE. Some other times, they are allowed to activate and control ICE but are not allowed to give any rights to use ICE to a third manufacturer (which is the case with SilverFast).

In case of the V600 we do not have a license from Epson to implement digital ICE in SilverFast.

Hence we are working on expanding the HDRi mode with more Epson scanners including the V500 and V600.

highyoyo wrote:I realize the v600 is a new scanner and isn't supported yet, but the v700 & v750 scanners also tout this ability. Is it supportable or invokable in Silverfast when scanning prints with these devices?

We are still testing the Epson Perfection V600 on our testing lab and correcting possible issues with the scanner. Most likely the scanner will be supported with version 6.6.1r4 of SilverFast.

Again, the digital ICE technology will not be supported in the Epson Perfection V600 in any way.

Still you can use SRD which is our software tool for scratch and dust removal

Cheers